Method and apparatus for feeding molten glass



NOV- 16, 1937` F. o. wADswoRTl-l 2,099,088

METHOD AND APPARATUS FOR FEEDING MOLTEN GLASS Original Filed June 25, 1934 2 Sheets-Sheet l Nov. 16, 1937. F. L. o. WADswoRTH 2,099,088

METHOD AND APPARATUS FOR FEEDING' MOLTEN GLASS Original Filed June 25, 1934 2 Shets-Sheet 2 u r lNvz-:NTOR

M @mfw Patented NovB 16, 1937 ATET GFFlCE METHOD AND APPARATUS FOR FEEDING MOLTEN GLASS corporation of Indiana Application June 25, 1934, Serial No. 732,216 Renewed January 14, 1937 22 Claims.

This invention relates to a pneumatic feeder for delivering a series of separately formed mold charges of molten glass from a continuous source of supply, and more particularly, to an improvement in the type of pneumatic feeder generally illustrated in McCauley Patent No. 1,322,318 issued November 18, 1919.

In the so-called McCauley type of feeder a succession of predetermined quotas of the material are periodically accumulated in, and eX- truded from, a segregation chamber Whichis positioned above, and has its lower end spaced from, a suitably shaped disch-arge orifice in the floor of the supply reservoir, by alternately connecting the interior of the chamber to sources of vacuum and pressure. While the segregation chamber may be manually moved up and down, relative to the discharge orice, to vary the area of the passage between the segregation chamber and the supply reservoir, and thus regulate the volume of the successively formed charges, the chamber is not moved, once the proper Volume is secured, and the passage remains Xed or constant during the continued operation of the feeder. The area of this passage is not only substantially constant but is so restricted, that when the chamber is connected to pressure, a portion of the glass in the chamber will be eX- pelled through the orice and not forced back through the passage into the supply reservoir. As -a result of having such a restricted passage betweenthe segregation chamber and the reservoir, the natural flow from the reservoir to the orifice at the end of the pressure period, is retarded; and when the glass in the chamber is subjected to vacuum or suction, there is a complete stoppage of flow through the orifice, and oftentimes, even a reversal of flow, whereby the material is retracted or dr-awn back through the orifice into the segregation chamber. This results in a considerable loss of time between the formation of successive mold charges, and materially retards the speed of operation of the apparatus.

45 The principal object of this invention is to provide a continuous flow feeder in which there is no reversal or stoppage of flow at the orifice, and in which the mold charges are delivered l therefrom in a continuously flowing stream hav- 0 ing regularly recurrent enlarged portions, connected together by sections of reduced diameters. I attain this object by automatically varying the -area of the passage between the segregation chamber and the supply reservoir, at the be- 5 ginning and end of each accumulation and extrusion period, in exact and regulated synchronism with the corresponding vacuum and pressure applications, thereby more eiciently and eiTectively controlling the iiow of the molten glass into and out of said chamber during each successive cycle of mold charge formation.

This method of procedure enables me to minimize, and in large part to eliminate, the loss of time and the concomitant arrest of the discharge due to the usual stopping and retardation of the outow of glass from the delivery orice during the application of the sub-atmospheric (vacuum) pressure; and also enables me to substantially augment the rate of discharge during the period of super-atmospheric pressure application. The effect of eliminating the arrest or retardation of the outiiowing glass and auginenting the rate of discharge during the pressure period7 also enables me to substantially increase the rate of mold charge formation, and eliminate to a great extent the chilling and loss of heat in the mold charge during its formation; and to also preshape the successive mold charges preliminary to their severance and delivery to the forming machine.

This and other objects, purposes and advantages of the present invention will be rendered apparent to those skilled in the particular art by the accompanying illustrations and descriptions of the two exemplary embodiments of this invention, wherein:

Figure I is a longitudinal vertical section through the center of the ow orice and the supply reservoir of one form of my improved feeder;

Fig. II is a rear elevation of the upper portion of the mechanism shown in Fig. I;

Fig. III is a sectional plan view on the plane III- III of Fig. I;

Fig. IV is a fragmentary section on the plane IV-IV of Fig. I;

Fig. V is a fragmentary sectional view on the plane of Fig. I showing the position of the parts when the segregation chamber is raised to its upper position;

Fig. VI is a longitudinal vertical section, similar to the one shown in Fig. I and illustrates another exemplication of my invention;

Fig. VII is a top plan view of the apparatus illustrated in Fig. VI With a portion of the mechanism broken away to show the parts beneath it;

Fig. VIII is an enlarged View of one of the roller elements of the mechanism illustrated in Figs. VI ,and VII;

Fig. IX is a longitudinal sectional view illustrating'a modified form of a portion of the apparatus shown in Fig. VI;

Fig. X isY a top plan view of the apparatus illustrated in Fig. IX;

Fig. XI is a developed circumferential section showing the cam track and supporting rollers which form a part of this same apparatus.

In the construction illustrated in Figs. I-V, inclusive, the parent pool or mass, from which the molten material is to be'fed, is contained in a forehearth I which extends out from the'front of a large melting tank or furnace (not shown). The forehearth I is provided, at its forward end, with a delivery chamber D formed in an annular block 2 which is mounted in an aperture in the floor of the forehearth and extends a substantial distance thereabove. The lower end of the chamber D is partially closed by a removable flow bushing or ring 3, which defines the size of the delivery orifice F, and which is held in position against the bottom of the forehearth by a plate 4 bolted to a plate 5 which in turn is bolted to the bottom of the forehearth I and supports the floor block 2.

In delivering a series of separately formed mold charges through' the orifice F, a quantity of the molten material in the forehearth is periodically accumulated in and expelled from a segregation chamber B formed in a reciprocating air bell 6 which is positioned above the floor block 2. The material is accumulated in the chamber B at the time when the bell is moved away vfrom the block 2 to open a passage G between the segregation chamber B and the forehearth I (see Fig. V); and the material is eX- rpelled therefrom, through the orice F, after the bellhas been moved toward the floor block 2 to restrict the passageway G (see Fig. I).

The bell 6, which is made of any suitable refractory material, extends upwardly through an opening in the roof of the forehearth and is rencircled by a refractory guard sleeve 'I which is provided with a shoulder 8, that is seated on the roof of the forehearth, and is heldin place by a metallic 'clamping member 9 secured thereto. This guard sleeve extends downwardly into the molten glass in the'forehearth chamber, and forms therewith a liquid seal that eiectually prevents the escape of hot gases from the roof opening.

The upper end of the bell 6 terminates in an enlarged head I6 which is engaged by a anged clampingring II, that is detachably secured to a cap I2 on the lower end of a tubular rod I3. The lower end of' this tube is in registry with a central passageway in the top of the bell 6, and its upper end is closed by an enlarged cap plate I5 that is threaded into an enlarged portion I6 of the bore. The rod I3 is slidably and rotatably supported in upper and lower bearings I1 and I8 which are carried by upper and lower crossheads, I9 and 20, that are mounted on the side posts, 2l-L2I, of the metal frame or boot which surrounds the forehearth structure.

In order to reciprocate the rod I3, and alternately raise and lower the bell 6,-and thus periodically open and close (or nearly close) the passageway G-I provide a flanged sleeve 22 which encircles the tubular rod I3, and is engaged by three adjustable set screws 23, that are threaded through the cap plate I5. The lower Vend of this sleeve is supported on a ring of balls 25 which are carried by a collar 24; and

this collar is, in turn, provided with laterally extending side arms 26-26 (see Fig. III) which are pivotally attached to the outer ends of a pair of slotted links 2`l-2I, that are rockably supported on a cross shaft 28. The inner (or right hand) ends of the links 2l are cross connected by another shaft 36, which carries two cam rollers 3I-3I that are engaged by the cams 32-32 on the shaft 33. This shaft is mounted in bearings 31E- 34 on the crosshead I5 and is provided with a sprocket wheel 36 which is continuously driven, in the direction of the arrow, Fig. I, from any suitable motor (none shown). As the cam shaft revolves the connected links 2"!-21 are rocked up and down on their cross rshaft support 28, and the collar -together with the parts, 22-I5-E3, supported thereonis raised and lowered to impart a corresponding movement to the bell 6.

In order to change the range of up and down movement of the bell members the rock shaft support 28-which passes through the slots in the links 2l, 2liis mounted in the upper ends of a pair of arms 3'i-3'I, which are rigidly connected to each other by a sleeve hub 33, and which are rockably supported on the crosshead I9 by the trunnion pin 39; and one of these arms is provided with a lateral extension 46 that is connected to the upper end of a rod 4I, which extends downwardly through an opening in the lower crosshead 26, and which is held in adjustable relation thereto by the lock nuts t2 and 42a.. By varying the position of these nuts the connected members 37-38 and 4Q may be rocked back and forth on the trunnion support 39 to shift the position of the rock shaft 28 in the slots, 29-29, and thereby alter the angular throw of the link arms, 21-21.

The downward movement of the bell 6 is limited by the lock nuts 43 which are threaded on the rod I3 and which are adapted to engage the upper surface of the bearing I8 and thus pref vent the actual physical contact of the lower end of the bell 6 with the adjacent surface of the annular floor block 2.

In order to facilitate the periodic accumulation of material in the chamber B, I provide means for connecting the communicating passageways in the bell 6 and its tubular support I3, with a vacuum conduit ZH; when the bell has been raised to its upper position. In the construction now under consideration, the connection is effected by providing theV rod I3 with a side port d which is moved into registry with an annular groove and passageway A5 in the upper bearing member I, and which is thereby put into communication with the valve chamber 46 and the vacuum conduit Ill.

The portion or quota of material being accumulated within the segregation chamber B is prevented from rising above a predetermined level therein, by an electrically operatedvalve i8 which is adapted to close the passageway 45 and thus shut oif further communication between the chamber B and the source of sub-atmospheric or vacuum pressure. The valve 58 is actuated by an electromagnet 46 positioned in the valve chamber 46 and having one of its terminals connected, (through the bearing Il', the rod I3 and the cap I2), with an electrode 56 that extends through the upper end of the bell 6 into the top of the chamber B; and having its other terminal connected (through the battery E and the insulated conductors 5I-5I) to a second electrode 52 that extends into the delivery chamber D. It is apparent that when the material, rising in the chamber B, comes in contact with the electrode 50, the battery circuit is closed and the magnet 49 is energized to lift the valve d8; thereby cutting oi communication between the Vacuum connection 4l and the chamber B, and arresting the further rise of molten material therein.

In order to assist the expulsion oi the glass from the chamber B provision is also made for the admission of compressed fluid thereinto at the time when the air bell 6 is in its lowermost pesition, and the passageway G, is correspondingly throttled to prevent or restrict the backiiow of molten material to the supply reservoir. As here shown (Fig. I) this action is effected by providing the tubular rod i3 with another lateral port open ing 55 which is brought into registry with an annular groove and passageway 55 in the upper bearing block I'l-when the rod is moved downand which is thereby put into communication with a valve chamber 5'! that is supplied with compressed air through a pipe 5E. The ow of air to the valve chamber 5T is controlled by a needle valve 59 whose stem is adjust-ably connected to the lower end of a slotted lever 5l that is rockably mounted on a vertically adjustable pivot block 62. The upper end or" the lever El carries a roller 64 which is engaged by a cam 55 on the shaft 33; and a coil spring E6, disposed between the head of the valve stem and the adjacent end of the valve chamber 5'! tends to hold the needle valve 59 in its closed position. The volume ci compressed uid delivered to the chamber B be further regulated by a plug valve 5'? which is mounted in the enlarged bore section la of the rod I3, and is manually operable through the stem 6l that is threaded into the cap l5. The opening and closing movements of the needle valve 59 may be varied, at will, by moving the pivot block 62 up and down on its bracket support 63, and by shifting the point of connection between the head of the needle valve stem and the lever 6|; and these two adjustments, together with that of the plug valve 6l furnish means for the complete control of the flow of compressed air to the upper end of the segregation chamber B.

In order to stir and agitate the material in the forehearth and thus prevent localized changes in the temperature or the physical composition of the material in the outer end thereof, I prefer to ,rotate the bell 5 during the operation of the feeder. This rotation is eilected through the irictional engagement of the cap screws 23 with the upper surface of the flanged sleeve 22 which in this case, is revolved, at a constant speed, by a spur gear l@ which is attached to the lower end of the sleeve 22, and which is engaged by an elongated pinion 'H that is keyed or otherwise secured to the hub of a worm wheel l2, and is driven by a worm 13 on the shaft 33. The connected gear elements 'H and 'i2 are revolubly mounted on a Xe-d stud bolt lli, which is carried by the crosshead I9; and the rotating sleeve members 22- 10 are also preferably supported-independently of the shaft member l3by a collar bearing 'i5 that is also carried by this crosshead.

In order that the position of the air bell d may be readily adjusted to vary the area of the passageway G, the upper crosshead is which supports the entire operative mechanism for reciprccat ing and rotating the bell members is slidably mounted on the posts 2 1 2 l, and is supported by worm wheel nuts dii-35 which are threadedthere on, and which may be turned in unison by a pair of worms BI-BI on the cross shaft 82. When the shaft 82 is rotated-e. g. by turning the handwheel 83-the crosshead I9 may be bodily raised and lowered, to vary the degree of opening of the passageway G, during the reciprocation of the air bell 5, without altering the range of the reciprocatory movement.

When it is desired to replace the air bell 6 for any reason, this member may be readily withdrawn from the forehearth by simply detaching the bearing i3 from the lower crosshead support 2li and connecting the cap l5 to the cable hook 33 of a suitable hoisting mechanism. The tubular rod i3 may then be drawn upwardly through the bearing l l and the encircling sleeve members H E, etc., without disturbing any of the other parts ci' the feeder assembly,

When the apparatus is to be shut down for the purpose of changing the air bell or any other reason, the glass in the forehearth l is prevented from flowing into the discharge chamber D by means of a gate or baille block 89 which is adapted to be lowered into contact with the iioor of the forehearth. The gate 89 extends through an opening in the roof of the forehearth, and is supported thereon by means of angle members 9B and 96a, (Fig. IV) which are clamped to the sides of the gate and rest upon the top of the furnace. Suitable pads of insulating material, 9i, may be disposed between the bottom of the angles and the roof of the forehearth to more eiectively seal the opening through which the block 89 passes, and prevent the gases in the forehearth from escaping therethrough. The top of the gate block 89 is provided with an enlarged head 92 which is engaged by angle bars 953-93 that are clamped against a cap Sli; and the latter is connected to a threaded rod 95 which extends up through the lower cressnead 2li, and is supported therefrom by an adjustable nut 95.

When the gate 89 is in its upper position, the lower end projects into the material in the forehearth and acts as a skimmer to prevent the impurities on the surface of the molten glass from flowing into the chamber D.

When the apparatus is in operation, and the are in the position shown in Fig. I, the air bell is depressed to throttle or restrict the supply passage G, and the cam 55 is holding t valve 5S in its open position to admit compressed air from the pipe 58, through the passages and ports 55-55 and the tubular rod i3 to the chamber B;-thus supplementing the action of gravity in expelling the molten material from the orifice F. When a suiiicient quantity oi this material has thus been expelled, the cam 55 releases the roller 6d and permits the spring 66 to close the valve 59; and concurrently therewith, or in close timed relationship thereto, the cams 32 come into action to rock the links 2'5-21 on their shaft support 28 and thus lift the interc; aged collar sleeve cap anc. tube members,

-'2-!5-i3, to raise the bell 6 and open the .ss-age G. As the rod i3 moves upwardly, the rt 55 moved out of register with the port and a residual quota of compressed air is `apped in the now closed. space above the surface cf the glass in the bell 6. This trapped body of compressed fluid acts to continue the expulsion of the molten material from the delivery orice while the bell is being lifted, and thus prevents any retardation or retraction of the outlowing stream by such upward movement. 'When the bell has nearly reached the upper limits or" its travel, and the passage G is substantially wide open, the port it comes in registration with the groove t5, and the interior of the bell is then connected through the pipe 41 to a suction pump or other suitable source of sub-atmospheric pressure; which correspondingly accelerates the flow of molten material from the forehearth, into the segregation chamber B.

Before the port 44 comes in registration with the recess 45, the passageway G, between the segregation chamber B and the forehearth I, is substantially wide open and molten material is then moving, under the influence of gravity, from the forehearth to the chamber D, and is flowing directly therefrom in an unrestrained stream through the orifice F. As a result of reestablishing this direct gravity flow from the main supply reservoir, before moving the ports 44 and 45 into registration, there is no retardation or arrest of the delivery from the orice F upon the initial application of suction to the chamber B; and the glass will be raised therein without materially affecting the concurrent outow through the orice. This attainment of this condition of non-arrested or non-retractive delivery is greatly facilitated by the fact that the area of the opened passageway G is much greater than that of the opening F; and the glass will therefore flow into the chambers D and B much more rap-idly than it can escape therefrom through the delivery orifice.

As the glass is drawn into the chamber B, under the action of the vacuum, it will rise therein until it comes into contact with the terminal 5U and complete the electrical circuit, through the electromagnet 49, thus lifting the valve 48 and closing the connection between the segregation chamber B and the vacuum conduit 41. This automatic closure of the Vacuum connection permits of the use of a relatively high vacuumwhich facilitates and accelerates the recharging of the segregation chamberwithout incurring any danger of overlling this chamber and choking the air passage toy the pipe opening I4.

As soon as the desired quantity of glass has been drawn into the bell B the cams 33 release the rollers 34 and permit the air bell 6 to drop, by gravity until the stop nuts 43 engage the upper end of the bearing I8. As the rod I3 starts to move downwardly the port d4 is moved out of registration with the groove 45, and near the end of 'this downward movementwhen the passageway G is substantially closed-the port 55 comes in registration with the recess 55 and compressed air is again admitted to the chamber B (under the control of the valves 59 and B'I) to assist the action of gravity in accelerating the outflow from the delivery orifice F. This completes one cycle of feeding action.

Figs. VI to VIII, inclusive, illustrate another exemplication of my invention in which an alternative form of operating mechanism is used for reciprocating and rotating the air bell. In this exemplication, as in the one previously described, the parent pool of molten material from which the mold charges are to be fed is contained in the forehearth ia having near its outer end, a delivery chamber D which is formed in a block 2a mounted in the floor of the forehearth. The bottom of the delivery chamber D is partially closed by the removable ow bushing or ring 3a that defines the size of the ow oriiice F. The bushing 3a is held in place by means of a plate 4a bolted to a plate 50, which in turn is bolted to the bottom of the forehearth and supports the block 2a.

In feeding a series of mold charges from the flow orifice F, a quota of material is segregated in a chamber B which is formed in a reciprocating air bell 6a that is positioned above and in axial alignment with the annular floor block 2a. This quota is accumulated in the chamber B when the bellia is raised to open the passageway G between the contiguous ends of the bell and delivery block members Eet-3a; and is expelled through the orifice F when the bell has been lowered to throttle and substantially close this passageway, and thus prevent any material backflow of the segregated charge into the forehearth or supply reservoir. The bell 6a extends upwardly through a sealing sleeve la, mounted in the roof of the forehearth, and terminates at its upper end in an enlarged head Ia which is engaged by the anged clamp ring I Ia and an associated cap plate I 2a. The clamping action of these connected members, on the head of the bell 5a, is in this case, supplemented by a tubular bolt of nichrome, or other suitable shearably resistant metal which passes up through the closed end of the bell 6a and is provided with a nut that is screwed down on the cap plate I2a. The cap plate i211 is, in turn, connected to a vertically extending tubular member i3d by means of a flange coupling I2b, and a lock nut I2C. The lower end of the tube ISa is slidably and rotatably mounted in a bearing Ia which is detachably bolted to collars 20a-25a, that are carri-ed by the forehearth frame posts 2Ia--2 Ib; and the upper end of this tube extends through a triangular shaped frame Ila which is slidably mounted on these same posts, and is supported in position thereon by an interconnected set of nuts which will be described later.

In order to rotate the air bell 6a, and thus stir or agitate the material in the outer end of the forehearth, the bell 6a and tube i3d are supported on a constantly revolving annular head IBS which is engaged at its center with a hemispherical head IUI that is splined to the tube i3d, and is held in an axially adjustable position thereon by a gear nut |02. The head I is supported on, and frictionally driven by rollers |53- I93-I 03 secured to the outer ends of shafts HB4- IiM-il rotatably mounted in suitable bearings on the frame I'Ia and which are rotated, in unison, in the same direction and at the same speed, by a train of interengaged bevel gears B65-IS5- IBE-IGI-IBE-IUB. This train of gearing is driven from a sprocket wheel Iil, which is secured to the outer end of one of the' shafts H34, and is connected to a suitable motor, (not shown), by the sprocket chain Ia.

In order to periodically raise and lower the air which projects beyond the periphery thereof; Vand i at each revolution of the positively driven rollers this projecting lug engages the under face of the head IGI), and acts to lift this member, and with it the connected bell support elements IEI-I E32- I3a-I2b, etc. The return downward movement of the bell 5a is limited by meansV of the double lock nuts II!) which are adjustably mounted on the tube I3a above the bearing i3d.

In order to alternately connect the segregation chamber B to sources of vacuum and of pressure, when the bell is successively raised and lowered, the upper end of the tube I3a is provided with an annular valve housing I I I which is clamped thereto by a flanged screw plug I I6, and which is divided into two chambers, I IZ--I I3, that are respectively connected, by the pipes II-I I5, with suitable sources of sub-atmospheric and superatmospheric pressures. The valve chambers ||2| I3 are respectively connected with the interior of the tube |3a by ports |I1 and IIB in the Wall of the tube; and the admission of the sub-atmospheric and super-atmospheric pressures to these chambers is controlled by valves I IS-I 26 mounted therein and operated by the up and down movement of the valve housing III. When the connected tube and housing members |3a-I II move downward the valve IIS is closed by the frictional engagement of its stem |22 with a split bearing in the end of a stationary shelf |23 on the upper triangular crosshead frame I1a; and the valve |26 is positively opened by the engagement of the valve stem collar |25 with the upper surface of this same shelf. When the members |Sa||| are raised, the valve |26 is seated and carried upwardly with the valve housing, while the valve H9 is positively opened by the engagement of the valve stem collar |2| with the under side of the shelf |23. When the valve I 2) is opened compressed air is admitted from the conduit I I to the upper end of the bell 6a; and supplements the action of gravity in eX- pelling the molten material from the chamber B (the passage G now being substantially closed) and when the valve I I9 is opened the air is withdrawn from the bell chamber by its connection with the vacuum conduit lili; and the glass is drawn from the main forehearth reservoir into the chamber, through the now wide open passage G.

In order to prevent the molten material from being raised beyond a predetermined level in the chamber B, when it is subjected to a low subatmospheric pressure, I here provide a hollow fioat |32, of refractory metal; which is connected, by a threaded stem IBI, with an adjustable disc valve |36, which is adapted to close the lower end of the tube l3nt when the iioat |32 is lifted by the rising column of glass in the bell chamber. This valve is held closed by the upward pressure on the iloat and by the suction on its upper side, until compressed air is again admitted to the tube Ilia (on its downward movement).

In order to vary the area of the passageway G, I provide dual mechanisms, one of whichA is for turning the gear nut |52 to move the head IBI up or down on the tube I 3a; and the other of which is adapted to raise or lower the frame Ila on the posts 2 I a-Z Ib. The mechanism for turning the gear |62 comprises a pinion |35 which is secured to the end of a vertical shaft |36 that is slidably journaled in the shelf |23 and can be moved up and down to bring the pinion |35 into and out of mesh with the gear I @2. The shaft |36 is raised and lowered by a bifurcated shift lever |31, which is keyed to a short horizontal shaft |38, that is journaled in a bracket I 6| on the shelf |23, and is provided with a second lever |39 from which a'hand rod |46 is extended downwardly to a point within easy reach of the machine tender. The gears |35 and |62 are engaged by pulling down on the rod |46; and when this has been done, the shaft |35 may be rotated to move the gear nut |62 up or down on the tube I3a by means of the wire cord and pulley elements |42-Hl3-I63.

The mechanism for moving the frame Ila up and down on the posts 2|a-2Ia and 2lb comprises sprocket wheel nuts I45--I5-Ill5 which are threaded on the posts 2|a-2Ia--2Ib and which are connected together by a sprocket chain I 46, so that they may be turned in unison by a handwheel |41 secured to one of the sprocket Wheels |45.

In Figs. IX, X, and XI, I have illustrated another arrangement of operating means for reciprocating and rotating the air bell 6a; and for controlling the applications of pressure and vacuum to the glass in the segregation chamber B. In this construction, the upper end of the tube |3a is threaded into the hollow hub |56 of an annular head |5| which is provided with adjustable set screws |52, that are adapted to engage the upper surface of a large spur gear |53. This gear member is slidably and rotatably mounted on a central guide bearing |54, which is carried by the triangular crosshead frame I'Ia, and is supported on three rollers I 55|55| 55, that are revolvably mounted on the xed stud bolt journals |55a-I55a--I55a- It is rotated at any desired speed by a small pinion |56 which is mounted on a vertical stud bolt |51, and which is driven from any suitable motor (not shown) through the bevel gear elements |58-|59.

In order to periodically raise and lower the air bell 6a during the rotation of the gear I 53, the lower surface thereof, which rides on the rollers |55--I55-I55, is provided with a series of uniformly spaced cam projections ISI-IBI (sce Fig. XI), which successively engage these rollers, and raise the engaged members |53|5||3a, etc., as they pass over the roller supports.

In order to alternately connect the chamber B to sources of pressure and of vacuum, when the bell is in its lowermost and uppermost positions, the upper end of the hub |50, is closely engaged with a stationary cup-shaped casing |65, which is connected, by means of pipes IE6-|61, to suitable sources of super-atmospheric and subatmospheric pressures. The pipe |66 communi- Cates with an annular groove |68 on the surface of the hub |50, which is pierced by a series of radial ports |6811.; and the pipe |61 communicates with the upper closed end of the casing |65 through the passageway |69. The port openings |68a between the groove |68 and the interior of the hub |50, and the central opening between the upper end of the casing |65 and the hub cavity are all jointly controlled by a combination poppetsleeve valve ITB-HI, which is provided with an upwardly extended stem |12 that is slidably mounted in an adjustable plug |13 in the closed end of the casing; and which is normally held against the end of this plug by the spring |14. When the bell members Ga-I3a., etc. are in their raised position (as shown in Fig. IX) the head of the poppet valve element is unseated and communication is thus established, through the ports |1Ia, between the vacuum conduit connections |61--I 69, and the interior of the bell tube |3a. The resultant exhaustion of air from the segregation chamber B induces a rapid inflow of glass through the now wide open supply passage G, and a correspondingly accelerated accumulation of molten material above the delivery oriice, without arresting the continuous gravity discharge therefrom. The rapidity of this recharging, or accumulation action can be controlled by the adjustment of the plug |13 which controls the degree of opening of the poppet valve |16.

On the downward movement of the bell supporting members I3a and IED-which occurs when the cam projections |6| are carried past the rollers ISE-the poppet valve element |10 is seated. and if necessary carried down with the descending member |50 (against the tension of the spring |14) and the ports |68a are uncovered, thus establishing communication between the compressed air supply conduit |66 and the bell tube |3a, and subjecting the previously accumulated charge of glass in the chamber B to superatmospheric pressure that will supplement the action of gravity in expelling the molten material from the delivery orifice ;-the passageway G being now throttled, or closed to such a degree as to prevent any material backflow to the forehearth or supply reservoir.

The admission of compressed air to the interior of the chamber B is regulated and controlled by a needle valve |15 which is normally held in its closed position, by the coil spring |16, and which can be periodically opened by the action of a cam |11 on the hub of the bevel gear |58. In order to vary the time and the degree of opening of this valve the actuated and actuating elements (|15--|11) are connected by a slotted lever |19, which is rockably mounted on a vertically adjustable pivot pin |18; and by raising and lowering this pin the angular movement of the lever-and the resultant linear movement of the valve |15-can be controlled at will.

In order to momentarily establish a normal atmospheric pressure in the chamber B--intermediate the establishment of a sub-atmospheric and a super-atmospheric pressure thereinthe tube |3a may be provided with a lateral port opening |8| which is adapted to be brought into registry with a relief port |82 in a vertically adjustable collar |83, that is slidably engaged with the tube |3a. The collar |83 is so adjusted that the ports ISI-|82 move pastveach other at the time when the tube I3@ is cut off from communication with both of the conduits |65 and |61; and as a result of this the compressed air which is trapped in the segregation chamber B, by the closing of the ports |58a (on the upward movement of the bell tube |3a) is permitted to escape before the vacuum valve |1 is opened, and the effect of this opening is more immediate than it otherwise would be.

The operation of the apparatus illustrated in Figs. VI to XI inclusive, is substantially the same as that of the apparatus shown in Figs. I to V, inclusive; and the characteristic functional performance of these several illustrative embodiments of my invention should now be apparent, to those skilled in this art, without further eX- planation. There is, however, one feature of these improved constructions which has not heretofore been specifically mentioned. It will be observed that in all of the forms of apparatus herein illustrated and described the rotary movement of the air bell (ii, 6a, Gb, etc.) is effected by a frictional engagement between a positively driven member (e. g. 1E), |3 or |53), and other bell supporting members, (e. g. the parts 22-23, or IBO-IDI, or IBI-|52), so that if the bell encounters any unusual or abnormal resistance to rotation these engaged parts will slip on each other, and will not impose such a strain on the heated refractory material as will cause it to fracture or spall. This frictional driving action may also be utilized to automatically control the speed of rotation of the bell in accordanceY with the temperature and viscosity of the molten glass in which its lower end is immersed. It will also be observed that the slip nuts (43, or Hi), etc.), which limit the downward movement of the bell, maybe so adjusted with respect to the position of the driving members (1B, I3or |53) that when the bell is lowered the engagement between the driving and driven elements will be broken, and the bell will therefore remain at rest in its lowered position, and will be rotated only when it is lifted away from the adjacent ends of the delivery sleeves 2 or 2a.

From the foregoing description of these eX- emplifications of my improvements, it is apparent that I have provided an improved pneumatic feeder of the so-called McCauley type in which these is no loss of time between the formation of successive mold charges because there is never any arrest or stoppage of the flow, and no retraction ofthe glass in the orifice at the commencement of the vacuum application; and in which there is a continuous gravity discharge that is periodically accelerated by the application of a super-atmospheric pressure to material above the delivery orifice. As a result of these cooperative and complementary actions, the glass is extruded in a continuously flo-wing stream which presents a regularly recurrent series of enlarged sections, connected together by other sections or necks of reduced diameter.

It is further apparent that, since there is no arresting or retraction of the ow of glass, be-

tween the periods of accelerated delivery, I not only eliminate a loss of time between the formation of the successive mold charges, but I also materially decrease the heat losses and other difficulties that are encountered in an intermittent or interrupted formation of individually arrested and suspended gobs. It will also be obvious that, as a result of restricting the passage Y between the segregation chamber and the forehearth during' the application of a supplemental pressure to the outflowing glass, a more effective and more perfectly controlled extrusion action is obtained, and a lower pressure may be used for producing any given rate of Vdischarge from the delivery orifice. As a result of this a better regulation both of the weight, or volume, and of the shape, or contour of the successively formed stream sections, is made possible; and the desired regularity of action-in the formation of uniform mold charges-is less subject to disturbance by changes in the temperature or physical condition of the moltel glass.

I desire it to be understood that I have devised various mechanisms and procedures for feeding a continuously owing stream of molten glass which is adapted to be severed to produce mold charges, and that such mechanisms and procedures not only structurally and functionally distinguish from the features herein claimed, but form the subject matter of and are claimed in copending applications for patent.

What I claim as new and desire to secure by Letters Patent is:

1. A feeder for delivering successive mold charges through a submerged orifice, comprising a reciprocable bell above said orifice, means for reciprocating said bell, means responsive to the movement of the bell away from said orice for connecting the interior thereof to a source of subatmospheric pressure as the bell approaches the upper end of itsy stroke, means responsive to the movement of the bell toward said orifice for connecting the interior thereof to a source of super-atmospheric pressure at the end of its downward stroke, and means for maintaining such latter connection at the beginning of the upstroke of the bell to trap a quantity of said super-atmospheric pressure in said bell and preaoeaoss vent the retarding of flowing material through the orifice.

2. A feeder for delivering successive mold charges through a submerged orifice, comprising a reciprocable bell above said orifice, means for rotating said bell, means for alternately moving said bell toward and away from said orifice, means for introducing Super-atmospheric and sub-atmospheric pressures into Said bell at opposite ends of its travel, and means responsive to the glass level within said bell for automatically shutting off the delivery of sub-atmospheric pressure to said bell.

3. A pneumatic feeder, comprising a bell, means for rotating said bell, means for reciprocating said bell, means for connecting the interior of said bell to super-atmospheric pressure at one end of its travel, means for connecting the interior of the bell to sub-atmospheric pressure at the other end of its travel, means responsive to the glass level within said bell for automatically breaking the connection between the bell and the source of sub-atmospheric pressure, and means for adjusting the down stroke of said bell.

4. A feeder for delivering molten material through a submerged orifice in a forehearth comprising an air bell positioned in said forehearth above said orifice, a tube connected to said bell and communicating with the interior thereof, an annular head adjustably secured to said tube, means for frictiorially driving said head, means carried by said driving means for periodically raising said head to raise said bell, and means for connecting said tube to super and sub-atmospheric pressures at opposite ends of its movement.

5. A mechanism of the character described comprising a bell, a tube extending upwardly yfrom said bell, an annular head adjustably mounted on said tube, a frame surrounding said head, rollers on said frame engaging the underside of said head, means for driving said rollers to rotate said head, means on said rollers for periodically lifting said head and bell, means for introducing super-atmospheric pressure into said bell when the head is in its lowermost position, and means for introducing sub-atmospheric pressure into said bell when the head is raised by said rollers.

6. The method of delivering individual mold charges from a parent body of molten glass, which consists in establishing a gravity ow through an orifice submerged by said material, subjecting a portion. of the material to suction to segregate a quota of material above the orifice while maintaining the full gravity fiow therethrough, controlling the quantity of material segregated by the level of such segregated quota, and then materially restricting the ow from the parent body to the orifice while expelling the segregated quota through the orifice.

7. The method of delivering individual mold charges from a parent body of such material, which consists in establishing a gravity flow through an orice submerged by said material, segregating a quota of material in a reciprocating chamber positioned above the orifice while maintaining the gravity flow therethrough, utilizing the glass level `within said chamber to control the quantity of material segregated therein, materially restricting the flow from the parent body to the orifice, discharging the segregated quota through the orifice while such flow is restricted, and then removing the restriction to flow from between the parent body and the orifice just prior to the complete expulsion of said segregated quota.

8. A method of feeding molten glass in a suspended stream through an orifice submerged by a pool of such material which consists in segregating a quota of material in a chamber positioned above the orifice, controlling the quantity of material segregated by the glass level in said chamber, moving the chamber toward the orifice to prevent a reversal of flow from the chamber to the pool, discharging the segregated quota through the orifice, and then moving the chamber away from the orifice while maintaining a progressively varied pressure therein.

9. A method of feeding molten glass in a suspended stream through an orifice submerged by a pool of such material which consists in segregating a quota of material in a chamber positioned above the orifice, automatically controlling the quantity of material delivered to said chamber by the glass level therein, moving the chamber toward the orifice to restrict the passage between the pool and the orifice, discharging the segregated quota through the orifice, moving the chamber away from the orifice while maintaining a progressively decreasing pressure therein, and then segregating another quota of material within the chamber.

l0. A method of feeding molten glass in a suspended stream through an orifice submerged by a pool of such material which consists in establishing a gravity fiow of such material from the pool and through the orifice, accumulating a quota of material in a bell positioned above the orifice while maintaining such gravity flow therethrough, utilizing the glass level within said bell to control the quantity accumulated therein, periodically moving said bell toward said orifice to restrict the flow from the pool to the orifice, applying an expelling force to the quota in said bell to discharge it through the orifice during the period of restricted fiow, and then removing the restriction between the pool and the orifice while maintaining a progressively varied expelling force within the chamber.

1l. An apparatus for feeding molten glass comprising a forehearth having a flow orifice in the bottom thereof, an air bell reciprocably mounted above said orifice, means for reciprocating said bell, a valve operable in response to the movement of the bell toward the orifice for connecting the interior of the bell to a source of fluid pressure, means for holding said valve open at the beginning of the movement of the bell away from said orice to trap a quantity o-f fluid pressure within said bell to prevent retraction of the glass at the orifice, and a valve operable in response to the movement of the bell away from the orifice for connecting the bell to a source of vacuum as it approaches the upper limit of its travel.

12. An apparatus for feeding molten glass comprising a forehearth having a flow orifice therein, an air bell reciprocably mounted above the orifice and extending into the glass within said forehearth, means for reciprocating said bell to alternately restrict and open the passageway between said pool and the orifice, means for connecting the bell to a source of fluid pressure when said passageway is restricted, means for trapping a predetermined quantity of iiuid pressure within said bell as said bell begins to move away from the orifice to open the passageway between the pool and the orifice, means for connecting the bell to a source of vacuum when the passageway between the pool and the orifice is fully open, and means responsive to the glass level within said bell for automatically closing the connection between the bell and the source of vacuum.

13. A feeder for delivering successive mold charges to a submerged orifice comprising a reciprocable bell above said orifice, means for reciprocating said bell, means controlled by the movement of said bell away from the orifice for connecting said bell to a source of sub-atmospheric pressure, means controlled by the movement of said bell toward said orice for connecting said bell to a source of super-atmospheric pressure, means for momentarily maintaining such last mentioned connection at the beginning of the upstroke of said bell to trap a quantity of super-atmospheric pressure in said bell and prevent the retarding of the flowing material through Ythe orifice by such movement of the bell, and means responsive to the glass level Within said bell for closing the connection between said bell and the source of subatmospheric pressure irrespective of the movement of said bell.

14. An apparatus for feeding molten glass comprising a forehearth having'a flow orifice therein, a bell reciprocably mounted abo-ve the orifice and extending into the glass in said forehearth, means for reciprocating said bell to alternately restrict and open a passageway between said pool and said orifice, means controlled by the movement of said bell toward said orifice for connecting said bell to a source of fluid pressurewhen said passageway is restricted, means' for momentarily maintaining'said last mentioned' connection to trap a predetermined quantity of iiuid pressure within said bell on the initial movement of the bell away from the orifice to open the passageway between the pool and the orifice to prevent any retraction of the material flowing through the orifice, and means controlled by the movement of the bell away from the orifice and adapted to be operated thereby when the passageway between the pool and the orifice is fully open for connecting the bell to a source of vacuum.

15. A method of feeding molten glass in a suspended stream through an orifice submerged by a pool of such material, which consists in establishing a gravity flow of molten glass from said pool and through said orifice, accumulating a quota of molten glass in a bell reciprocating above said orifice, controlling the quantity of glass so accumulated in accordance with the level of the glass within said bell, and then discharging the accumulated quota from said bell and through said orifice.

16. A method of feeding molten glass in a suspended stream through an orifice submerged by a pool of such material, which consists in reciprocating a bell above said orifice to first establish a flow of glass from said pool and through said orifice and toy then restrict such flow, connectingthe interior of said bell to a source of vacuum while the fiow of glass from the pool through the orifice is established to accumulate a quota of glass therein, utilizing the glass level within said bell to close said vacuum connection to control the amount of glass Aso accumulated and then discharging Ythe accumulated quota from said bell and through said orifice during the period of restricted flow.`

17. A method of feeding molten glass in a sus- .fice to first establish a flow from said pool through said orifice and to then restrict such flow, accumulating a quota of glass withinvsaid bell during the period of unrestricted flow from the pool through the orifice, utilizing the glass level within said bell to control the quantity so accumulated therein, and discharging the accumulated quota from the bell and through the orice while the flow from the pool through the orifice is restricted.

18. A method of feeding molten glass in a suspended stream through an orifice submerged by a pool of such material, which consists in moving a bell alternately away from and toward said orifice to rst establish a flow from said pool through said orifice and to then restrict such iiow, accumulating a quota of glass within said bell during the period of unrestricted iiow from the pool through the orifice, utilizing the glass level within said bell to control the quantity of glass so accumulated therein, applying a discharging force to the accumulated quota within said bell while the iiow from the pool to the orifice is restricted to discharge such quota through the orifice, and continuing the application of such force after the bell has started moving away from said orifice.

19. A method of feeding molten glass in a suspended stream through an orifice submerged by a pool of such material, which consists in moving a bell alternately away from and toward said orifice to first establish a gravity fiow from said pool through said orifice and to then restrict such flow, connecting the interior of such bell toa source of suction during the period of unrestricted iiow from said pool through said orifice to accumulate a quota of glass therein, utilizing the glass level within said bell to close said suction connection, applying a discharging force to the accumulated quota within said bell while the iiow from the pool to the oriiice is restricted, and continuing the application of such force after the bell has started to move away from said orifice.

2G. A glass feeder comprising a forehearth having an outlet in the bottom thereof, a bell'projecting into said forehearth in alignment with said outlet, means foralternately moving said bell toward and away from said outlet, means for introducing superatmospheric and subatmospheric pressures into said bell at opposite ends of its travel, and means responsive to the glass level within said bell for automatically shutting off the delivery of subatmospheric pressure thereto.

21. A glass feeder comprising a forehearth having an orifice in the bottom thereof, a bellprojecting into said forehearth in alignment with said orifice, friction means for rotating and reciprocating said bell, and means for connecting said bell to sources of superand subatmospheric pressures at opposite ends of its reciprocable movement.

22. A glass feeder comprising a forehearth having an orifice in the bottom thereof, an air bell projecting into said forehearth above said orifice, means for rotating and reciprocating said bell including friction rollers having cam-like projections thereon, and means for connecting said bell to sources of superand subatmospheric pressures at opposite ends of its reciprocable movement.

FRANK L. O. WADSWORTH. 

